/*
 * Copyright (C) 2008-2008 LeGACY <http://www.legacy-project.org/>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef __LEGACY_GRID_H
#define __LEGACY_GRID_H

/*
 @class Grid
 Grid is a logical segment of the game world represented inside LeGACY.
 Grid is bind at compile time to a particular type of object which
 we call it the object of interested. There are many types of loader,
 specially, dynamic loader, static loader, or on-demand loader. There's
 a subtle difference between dynamic loader and on-demand loader but
 this is implementation specific to the loader class. From the
 Grid's perspective, the loader meets its API requirement is suffice.
 */

#include "Platform/Define.h"
#include "Policies/ThreadingModel.h"
#include "TypeContainer.h"
#include "TypeContainerVisitor.h"

// forward declaration
template<class A, class T, class O> class GridLoader;

template
<
class ACTIVE_OBJECT,
class WORLD_OBJECT_TYPES,
class GRID_OBJECT_TYPES,
class ThreadModel = LeGACY::SingleThreaded<ACTIVE_OBJECT>
>
class LEGACY_DLL_DECL Grid
{
	// allows the GridLoader to access its internals
	template<class A, class T, class O> friend class GridLoader;
	public:

		/** destructor to clean up its resources. This includes unloading the
		 *  grid if it has not been unload.
		 */
		~Grid() {}

		/** an object of interested enters the grid
		 */
		template<class SPECIFIC_OBJECT> bool AddWorldObject(SPECIFIC_OBJECT *obj, OBJECT_HANDLE hdl)
		{
			return i_objects.template insert<SPECIFIC_OBJECT>(hdl, obj);
		}

		/** an object of interested exits the grid
		 */
		template<class SPECIFIC_OBJECT> bool RemoveWorldObject(SPECIFIC_OBJECT *obj, OBJECT_HANDLE hdl)
		{
			return i_objects.template remove<SPECIFIC_OBJECT>(obj, hdl);
		}

		/** Accessors: Returns a specific type of object in the WORLD_OBJECT_TYPES
		 */
		template<class SPECIFIC_OBJECT> const SPECIFIC_OBJECT* GetWorldObject(OBJECT_HANDLE hdl, SPECIFIC_OBJECT* fake) const { return i_objects.template find<SPECIFIC_OBJECT>(hdl); }
		template<class SPECIFIC_OBJECT>       SPECIFIC_OBJECT* GetWorldObject(OBJECT_HANDLE hdl, SPECIFIC_OBJECT *fake)       { return i_objects.template find<SPECIFIC_OBJECT>(hdl, fake); }

		/** Refresher/update the grid. This required for remote grids.
		 */
		void RefreshGrid(void) { /* TBI */ }

		/** Locks a grid. Any object enters must wait until the grid is unlock.
		 */
		void LockGrid(void) { /* TBI */ }

		/** Unlocks the grid.
		 */
		void UnlockGrid(void) { /* TBI */ }

		/** Grid visitor for grid objects
		 */
		template<class T> void Visit(TypeContainerVisitor<T, TypeMapContainer<GRID_OBJECT_TYPES> > &visitor)
		{
			visitor.Visit(i_container);
		}

		/** Grid visitor for world objects
		 */
		template<class T> void Visit(TypeContainerVisitor<T, TypeMapContainer<WORLD_OBJECT_TYPES> > &visitor)
		{
			visitor.Visit(i_objects);
		}

		/** Returns the number of object within the grid.
		 */
		unsigned int ActiveObjectsInGrid(void) const { return i_objects.template Count<ACTIVE_OBJECT>(); }

		/** Accessors: Returns a specific type of object in the GRID_OBJECT_TYPES
		 */
		template<class SPECIFIC_OBJECT> const SPECIFIC_OBJECT* GetGridObject(OBJECT_HANDLE hdl, SPECIFIC_OBJECT *fake) const { return i_container.template find<SPECIFIC_OBJECT>(hdl, fake); }
		template<class SPECIFIC_OBJECT>       SPECIFIC_OBJECT* GetGridObject(OBJECT_HANDLE hdl, SPECIFIC_OBJECT *fake)       { return i_container.template find<SPECIFIC_OBJECT>(hdl, fake); }

		/** Inserts a container type object into the grid.
		 */
		template<class SPECIFIC_OBJECT> bool AddGridObject(SPECIFIC_OBJECT *obj, OBJECT_HANDLE hdl) { return i_container.template insert<SPECIFIC_OBJECT>(hdl, obj); }

		/** Removes a container type object from the grid
		 */
		template<class SPECIFIC_OBJECT> bool RemoveGridObject(SPECIFIC_OBJECT *obj, OBJECT_HANDLE hdl) { return i_container.template remove<SPECIFIC_OBJECT>(obj, hdl); }

	private:

		typedef typename ThreadModel::Lock Guard;
		typedef typename ThreadModel::VolatileType VolatileType;

		TypeMapContainer<GRID_OBJECT_TYPES> i_container;
		TypeMapContainer<WORLD_OBJECT_TYPES> i_objects;
};
#endif
